Carbon Brushes

Carbon Brushes

A carbon brush is a sliding contact used to transmit electrical current from a static to a rotating part in a motor or generator. Mersen is one of the few manufacturers that develops and produces its own brush grades in-house, drawing on more than 130 years of tribology expertise.

Thanks to vertical integration from raw carbon material to finished brush, every grade is engineered for specific current densities, peripheral speeds, slip ring materials and operating environments. The result: longer brush life, lower wear and fewer unplanned interventions. Selecting the correct grade is the single most important factor in brush life and maintenance interval.

Wind turbines: CG677 is compatible with both bronze and stainless steel slip rings and is the most widely deployed wind grade; CG626 is recommended for high current density at peripheral speeds up to 45 m/s, and MC837 with higher copper content for elevated current densities under variable load. Brushes are co-designed with Mersen brush holders for correct spring pressure and contact stability.

• Wind generators (DFIG) — CG626, CG677, MC837
• Wound-rotor / slip ring motors — metal-graphite and electrographite grades
• DC motors (traction, process) — full range of electrographite grades
• Pitch motors, signal transmission — graphite signal grades
• Grounding and lightning protection — metal-graphite (copper, silver)
• GE-Hitachi 1.X platform — HCH-30X / HCH-4X1 phase and ground grades

Technical Specifications

Carbon Brushes for Motors and Generators (PDF) TDS-01 Functions of a Good Brush (PDF) TDS-20 Brushes for Slip Rings (PDF) Manufacturer Product Page